Is matter around us pure Worksheet-3
A. heat changes in liquid state
B. convection currents
C. impact of molecules of dispersion medium on on dispersed phase
D. attractive forces between the particles of dispersed phase and dispersion medium.
A. crystallisation B. hand pricking
C. by sublimation D. centrifugation
A. rusting of iron B. cooking of food
C. freezing of water D. digestion of food.
A. starch solution B. sodium chloride solution
C. copper sulphate solution D. sugar solution.
A. 10–5 cm to 103 cm B. 10–5 cm to 10–7 cm
C. 10–2 cm to 10–4 cm D. None is correct.
A. two miscible liquids B. any two liquids
C. any two gases D. two immiscible liquids
A. naked eye B. ordinary microscope
C. electron microscope D. telescope.
A. an element only
B. a compound only
C. either element or compound
D. any substance.
A. sulphur B. bromine C. chlorine D. nitrogen
A. cloud B. smoke
C. gel D. soap bubble
Explanation: Zig-zag path of colloidal particles is called Brownian Movement. Zig-zag path of particles is due to collision of particles of dispersed phase and dispersion medium.
Explanation: Ammonium chloride sublimes where as sodium chloride melts on heating. A mixture of ammonium chloride and sodium chloride can be separated by sublimation.
Explanation: Freezing of water is a physical change. On freezing only state of water changes its chemical composition remains the same.
Explanation: Starch solution because it is a colloidal solution.
Explanation: It is between 10–5 cm to 10–7 cm to 10–7 cm (10–9 m)
Explanation: Emulsion is a mixture of two immiscible liquids. Milk, Cod liver oil, tonics in liquid form etc. are emulsions.
Explanation: Ordinary microscope is used to view colloidal particles.
Explanation: It can be either an element or a compound.
Explanation: Bromine is liquid at room temperature.
Explanation: In cloud, water drops are suspended in air.